President Obama made a rare and surprise visit to Afghanistan on Sunday for a Memorial Day weekend rally with U.S. troops.

Air Force One touched down at Bagram Air Field in the dark Sunday evening local time after secretly leaving the Washington area Saturday night.

Obama was expected to be briefed by military commanders and visit wounded service members at a hospital on the base. He was also to attend a rally, including a performance by country music star Brad Paisley, who traveled with the president.

Deputy National Security Advisor Ben Rhodes told reporters flying with the president that Obama has no meetings scheduled with either President Hamid Karzai or the two candidates in the runoff election to succeed him, Abdullah Abdullah or Ashraf Ghani. Rhodes said that the White House wanted to focus on the troops, not politics.

The visit comes amid a controversy over complaints that Veterans Affairs facilities have concealed long waits for health care during the Obama administration.

Obama declared this week that he will not tolerate misconduct at the Department of Veterans Affairs, but he is standing by VA Secretary Eric K. Shinseki pending a review of the full scope of the problem. Shinseki’s fate is probably tied to the outcome of a preliminary report due to the president next week.

Saul Loeb / AFP/Getty Images

President Obama is greeted by James Cunningham, U.S. ambassador to Afghanistan, at Bagram Air Field on Sunday. At far left is Gen. Joseph Dunford, commander of U.S. forces in Afghanistan and the multinational force there.

President Obama is greeted by James Cunningham, U.S. ambassador to Afghanistan, at Bagram Air Field on Sunday. At far left is Gen. Joseph Dunford, commander of U.S. forces in Afghanistan and the multinational force there. (Saul Loeb / AFP/Getty Images)

In the meantime, though, several Republicans and at least two Democrats have called for Shinseki's resignation. Claims that VA employees kept fake waiting lists have already become an election-year issue, and lawmakers are intent on holding the president accountable.

During his visit, Obama planned to meet with U.S. Ambassador James Cunningham and Gen. Joseph F. Dunford Jr. to get a battlefield update and to discuss troop levels beyond this year.

Obama has not yet made a decision about the size of a force to leave in place after the withdrawal this year, Rhodes told reporters on the fight to Afghanistan. In preparation for that decision, the White House thought it was important to hear from the commander on the ground and from the U.S. diplomatic corps in Afghanistan. The NSC held a meeting on the question of the post-withdrawal troop level.

“It is important for him to come before he articulates a decision.” Rhodes said.

Rhodes emphasized the U.S. need for a bilateral security agreement in place before there could be a post-2014 force in Afghanistan. Karzai has refused to sign such an agreement, but top advisors to the president hope that Karzai's successor will come to another conclusion. U.S. intelligence and Pentagon officials want to see some kind of American protection in the country to protect intelligence gathering and training for Afghan forces.

Rhodes acknowledged that Afghanistan is still a violent place, and said that there had been a recent shift in Taliban tactics from large-scale military operations to terrorism. But he also argued that there had been successes, including the fact that Afghan security forces have been in the lead in combat for months.

Rhodes said there would probably be “additional clarity” about the president’s thinking in Afghanistan over the coming days. Obama is expected to detail his second-term foreign policy approach during a Wednesday commencement speech at the U.S. Military Academy in West Point, N.Y.

While in Afghanistan, the president planned to visit wounded troops in the military hospital.

A larger event with active military personnel was to include country star Brad Paisley, who accompanied Obama on Air Force One for the 13-hour flight. Paisley, an Obama supporter, has performed at the White House.

Also traveling with the president were National Security Advisor Susan Rice, as well as senior advisors Dan Pfeiffer and John Podesta. Podesta has a son serving in Afghanistan, according to Scott Wilson, the Washington Post reporter serving as the representative for White House reporters on the trip.

Rhodes said the administration sees the trip as “an opportunity for the president to thank American troops and civilians for their service,” according to Stephen Collinson, an Agence France-Presse reporter also on the trip. Rhodes noted that Obama has not been to Afghanistan for two years and had been looking for an opportunity to get to the country.

Rhodes said the flap over the VA did not “factor into the planning for the trip,” but he said the president would stress the underlying general message of support in his administration for troops and veterans once they return home.

He said the Afghan political calendar also explained the decision not to meet with Karzai. But Collinson said the president had spoken to Karzai several times recently, including after a deadly landslide in Afghanistan.

Obama visited Bagram Air Force base twice in 2010 and once in 2012. In past visits, his message was mostly for Afghan authorities, whom he urged to clean up corruption and uphold the rule of law.

In his last visit, Obama was in the country to mark the completion of a 10-year Strategic Partnership Agreement guaranteeing continued economic and development aid and promising negotiations on a future security arrangement.